GWN Tools · Health

Water Intake Calculator

Estimate how much water to drink each day from your body weight and exercise time. Results in ounces, liters and cups. Switch between metric and imperial units.

kg
min
0 oz
0 L per day
recommended daily water intake
Ounces
0
Liters
0
Cups (8 oz)
0

Informational only — not medical advice. Food and other drinks count too; needs rise in heat or illness. Consult a professional.

About the water intake calculator

What is a water intake calculator? A water intake calculator estimates how much water you should drink in a day based on your body weight and how much you exercise.

How much water should I drink per day?

A common rule of thumb is to drink about half to two-thirds of an ounce of water per pound of body weight each day. This tool uses 0.5 ounces per pound as a baseline and 0.67 ounces per pound for active people, then adds about 12 ounces for every 30 minutes of exercise.

How is the daily water target calculated?

Daily ounces = body weight in pounds × 0.5 (baseline) up to × 0.67 (active), plus 12 ounces per 30 minutes of exercise. The result is also shown in liters (ounces × 0.0295735) and 8-ounce cups (ounces ÷ 8).

Does food and other drinks count toward water intake?

Yes. Water from food, tea, coffee and other beverages all contribute to your daily fluid intake, so you do not need to drink the full amount as plain water. Needs also rise in hot weather or illness. This is a general estimate only — consult a healthcare professional for personalized advice.